Scientists reveal the carbon footprint of your sandwich

Researchers at the University of Manchester have the distinguished honor of conducting the first-ever study on the carbon footprint of sandwiches. The research team analyzed the emissions impact of 40 different kinds of sandwiches, taking into account the entire life-cycle of everyone’s favorite quick lunch. The production of ingredients, food waste, packaging, and refrigeration were all accounted for to determine the true cost. According to their analysis, the “all-day” pre-made, store-bought breakfast sandwich, loaded with emissions-intensive pork, eggs, and cheese, is the least environmentally friendly sandwich option.

Scientists found that sandwiches containing pork, cheese, or prawns/shrimp had generally higher carbon footprints. However, the study also showed that a home-made ham and cheese sandwich had the lowest carbon footprint of sandwiches studied. Making your own sandwich rather ordering out was shown to have reduced that sandwich’s carbon emissions by half. The refrigeration required for store-bought sandwiches accounts for about a quarter of their emissions cost. Packaging is up to 8.5% of emissions, while transporting refrigerated ingredients and materials accounts for 4%.

This University of Manchester study is of particular interest to the British people, who consume more than 11.5 billion sandwiches each year. “Given that sandwiches are a staple of the British diet as well as their significant market share in the food sector, it is important to understand the contribution from this sector to the emissions of greenhouse gases,” study co-author Adisa Azapagic told the Guardian. “For example, consuming 11.5bn sandwiches annually in the UK generates, on average, 9.5m tonnes of CO2, equivalent to the annual use of 8.6m cars.” The worst offending all-day breakfast sandwich alone generates the emissions equivalent of a car driving twelve miles. Researchers recommend that ingredients with high-carbon footprints, such as meat, cheese, lettuce, and tomato, be limited or removed when making a sandwich. A less meat-and-cheese intensive sandwich also would be a healthier choice for personal health.